One of conventional art flat X-ray detectors is, for example, disclosed in U.S. Pat. No. 5,905,772.
An x-ray image diagnosis apparatus making use of such as the above referred to flat x-ray detector generally receives with the flat x-ray detector transmitted x-rays which are obtained when x-rays from a x-ray generator are irradiated on to a subject and obtains an x-ray image using respective channel outputs from the flat x-ray detector as image information.
As the flat x-ray detector, one in which an x-ray fluorescent substance is laminated on arrays of photo detector elements, for example, one in which a scintillator is laminated on photo diode arrays such as amorphous silicons is used, however, the sensitivity of the respective channels in the detector elements differs each other.
For this reason, the sensitivity information of the respective channels were determined in advance, and when image taking, the outputs of the respective channels were individually corrected by making use of the sensitivity information.
Further, in order to obtain a further accurate correction image, the collection of the sensitivity information was performed at least once in a day and the sensitivity information was thus updated.
However, in the above conventional art, x-rays had to be irradiated on to the flat x-ray detector at a time other than image taking of a subject so as to collect the sensitivity information of the respective channels.
Since the sensitivity information collection through the x-ray irradiation requires to collect separate sensitivity information for plural image taking modes, it took about ten minutes at one time for collecting the required sensitivity information.
For this reason a possibility of exposure to operators in association with the sensitivity information collection increased, at the same time, during the sensitivity information collection other works in the concerned inspection room, for example, the preparation of the inspection were restricted, therefore, a problem was given rise which makes it difficult to immediately perform an image taking after the sensitivity information collection.
The present invention was carried out in view of the above situation and the object of the present invention is to realize an x-ray image diagnosis apparatus which permits to collect sensitivity information for performing sensitivity correction of respective channels without irradiating x-rays on to the flat x-ray detector.